There is evidence that left-handers employing an inverted handwriting posture---with the hand held above the line of writing and the pen pointing toward the bottom of the page---have visual linguistic functions specialized to the left hemisphere and may rely on uncrossed motor pathways for visuo-motor responses. Left-handers employing the noninverted handwriting posture appear to have visual linguistic functions specialized to the right hemisphere, and like right-handers, rely on crossed motor pathways for sensory-motor responses in all modalities. Handwriting posture seems to be unrelated to the lateralization of speech and of acoustic functions. To further investigate the neural control of sensory-motor responses and to understand the relationships among lateralization for vision, audition, and touch, the two groups of left-handers and a group of right-handers are being tested for simple reaction time by the left and right hands to lateralized visual, auditory, and tactile stimuli. By comparing reaction times for homolateral versus heterolateral hand/sensory field combinations, inferences can be drawn regarding the pathways of neural control. The concordance or discordance of reaction-time asymmetries between the hands and between the two sensory half-fields across the three modalities can clarify the relationships among lateralization for vision, audition, and touch.